1. Field of the Invention
A method comprising the step of treating meat and meat products, including fish, poultry, fish products, and poultry products, with a stabilizing amount of rosemary extract or rosemary extract in combination singly or collectively with tocopherols, ascorbic acid, citric acid, or sodium tripolyphosphate, prior to exposure of said meat or meat products to ionizing radiation, enhances the flavor and shelf life thereof. In addition, the active antioxidant ingredients of rosemary extract may be used individually or collectively as a replacement for rosemary extract, these being carnosic acid, carnosol, and rosmarinic acid, which have been found equivalent to or superior to rosemary extract itself for purposes of the present invention when used in the specified concentrations as hereinafter set forth.
According to the present invention, such prior addition of rosemary extracts in combination singly or multiply with tocopherols, ascorbic acid, citric acid, or sodium tripolyphosphate to meat, fish, poultry, meat products, fish products or poultry products:
1) dramatically diminishes the development of characteristic radiation-induced "wet dog, burnt or metallic" off-flavors, PA0 2) delays the onset of oxidative rancidity during and subsequent to irradiation, PA0 3) greatly retards the development of meat flavor deterioration (warmed over flavor) when the substrate is later cooked, stored in a refrigerated state, and reheated, and PA0 4) preserves the seasoning flavor if the meat, fish, poultry, meat product, fish product, or poultry product is flavored with spices and/or herbs in whole, ground, or extracted form.
The present invention accomplishes all these benefits without compromising the intended purpose of food irradiation, namely, increasing food safety by decreasing the population of microorganisms in the substrate.
2. Prior Art
The ability of ionizing energy to preserve foods from microbial spoilage is well known and documented in the literature. The use of this technology is being driven by increasing incidents of sickness and death caused by food-borne pathogens. As many as 9000 deaths, annually, are believed to be caused by food-borne bacteria in the United States (Ronald C. Deis, Food Product Design, June 1998, pp. 99-105). Irradiation of meats is the only current commercially viable technology that can destroy all harmful bacteria on or in a raw product. The matter has been considered by Donald W. Thayer in Journal of Food Protection 56, No. 10, 831-833 (October 1993) in the article entitled "Extending Shelf Life of Poultry and Red Meat by Irradiation Processing".
The principles of radiation sterilization are ably summarized in a review by G. Maerker (Adv. Appl. Lipid Res. 1996, 2, pp. 95-141). Two types of radiation are currently employed for foods, gamma-radiation and electron beams. Said radiation exposure usually occurs in the temperature range of -196 deg. C to 20 deg C. Though differing in certain important aspects, in each case energy is transferred into the food product with the resultant formation of high energy oxidants and reductants. The most important of these in foods with relatively high water content (such as meats) are the hydroxyl radical and the hydrogen atom, which result from the dissociation of water. Other active materials formed in the radiolysis of water include hydrated electrons, hydrogen peroxide, and hydronium ion. These active species are responsible for the anti-microbial action of irradiation, but are also responsible for some adverse chemical effects in the irradiated foods, including development of off-flavors and aromas and a decrease in oxidative stability in subsequent storage. Methods to overcome these difficulties will have to be developed before irradiation of meats will be accepted by consumers. Although there is significant prior art directed at solving the problems associated with irradiation of meats and meat products, the prior art does not in any way disclose or suggest the solution provided by the present invention.